Development of EphA2 siRNA-loaded lipid nanoparticles and combination with a small\u2010molecule histone demethylase inhibitor in prostate cancer cells and tumor spheroids

Ezgi Oner,Ayse Gulten Kantarci,Bilge Debelec Butuner,Emir Bozkurt,Anne-Marie Baird,Stephen P Finn,Mustafa Kotmakci,Steven G Gray

doi:10.1186/s12951-021-00781-z

Abstract

BackgroundsiRNAs hold a great potential for cancer therapy, however, poor stability in body fluids and low cellular uptake limit their use in the clinic. To enhance the bioavailability of siRNAs in tumors, novel, safe, and effective carriers are needed.ResultsHere, we developed cationic solid lipid nanoparticles (cSLNs) to carry siRNAs targeting EphA2 receptor tyrosine kinase (siEphA2), which is overexpressed in many solid tumors including prostate cancer. Using DDAB cationic lipid instead of DOTMA reduced nanoparticle size and enhanced both cellular uptake and gene silencing in prostate cancer cells. DDAB-cSLN showed better cellular uptake efficiency with similar silencing compared to commercial transfection reagent (Dharmafect 2). After verifying the efficacy of siEphA2-loaded nanoparticles, we further evaluated a potential combination with a histone lysine demethylase inhibitor, JIB-04. Silencing EphA2 by siEphA2-loaded DDAB-cSLN did not affect the viability (2D or 3D culture), migration, nor clonogenicity of PC-3 cells alone. However, upon co-administration with JIB-04, there was a decrease in cellular responses. Furthermore, JIB-04 decreased EphA2 expression, and thus, silencing by siEphA2-loaded nanoparticles was further increased with co-treatment.ConclusionsWe have successfully developed a novel siRNA-loaded lipid nanoparticle for targeting EphA2. Moreover, preliminary results of the effects of JIB-04, alone and in combination with siEphA2, on prostate cancer cells and prostate cancer tumor spheroids were presented for the first time. Our delivery system provides high transfection efficiency and shows great promise for targeting other genes and cancer types in further in vitro and in vivo studies.

Highlights

SiRNAs hold a great potential for cancer therapy, poor stability in body fluids and low cellular uptake limit their use in the clinic
There was an approximately twofold increase in particle size of Cationic solid lipid nanoparticle (cSLN) when cationic lipid dimethyldioctadecylammonium bromide (DDAB) was substituted by DOTMA
Smear, which can be an indicator of loose Small interfering RNA (siRNA) binding, was observed at N/P ratios of 6 and 8 for DDAB-cSLN and 6 for DOTMAcSLN

Summary

Introduction

SiRNAs hold a great potential for cancer therapy, poor stability in body fluids and low cellular uptake limit their use in the clinic. Oner et al J Nanobiotechnol (2021) 19:71 complex heterogeneity, recent studies have focused on personalized medicine strategies that target tumor markers [3, 4] These innovative anticancer treatment approaches include the use of RNA interference (RNAi)-based therapeutics that silence oncogenes [5] or the use of selective anticancer agents that reorganize dysregulated epigenetic machinery in tumor cells [6]. SiRNA molecules require suitable carriers (viral vectors or non-viral delivery systems) for successful translation into the clinic These carriers are essential for the stability of siRNA molecules in body fluids, efficient uptake, and subsequent intracellular trafficking for desired efficacy [8]. To the best of our knowledge, there is no study using cSLNs for siEphA2 delivery

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